Hot-air furnace.



T. R. BRIEN.

HOT AIR FURNAGE.

APPLICATION FILED AUG. 23, 1909.

1,094,399. Patented Apr. 21, 1914.

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I COLUMBIA PLANQGRAPH c0.,wAsH1NGTON, D. c.

T. R. BRIEN.

HOT AIR FURNACE. APPLICATION FILED AUG/23, 1909.

1,094,399, Patented Apr. 21, 1914.

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M0 6 THEUEURE R. BRIEA TQ COLUMBIA PLANOGRAPH c0., WASHINGTON, D. c.

THEODORE R. BRIEN, OF WESTFIELD, MASSACHUSETTS.

HOT-AIR FURNACE.

menses.

Specification of Letters Patent.

Patented Apr. 21, 1914.

Application filed. August 23, 1909. Serial No. 514,287.

To all whom it may concern Be it known that I, Trmononn R. BRIEN, a

citizen of the United States, residing at Nestfield, in the county of Hampden and Commonwealth of Massachusetts, have in rented certain new and useful Improvements in Hot-Air Furnaces, of which invention the following description, in connec tion with the accompanying drawings, constitutes a specification, such as will enable others skilled in the art to which the invention relates to construct and use the same.

The invention relates to improvements in the fire-boxes of hot-air furnaces and to novel construction and combination of the air and smoke flues thereof, and especially to an integral dome for the fire boX in which said combination of hot air and smoke flues is embodied.

The invention is fully disclosed in the drawings in which Figure 1 shows a semi-frontal and a semicross-sectional elevation of a furnace embodying my improvements. Fig. 2 is a side view in elevation of the interior of such a furnace with a part of the side wall of the fire box and dome broken away to show a part of the interior of the dome. Fig. 3 is a broken horizontal plan of the furnace showing in the upper right hand corner a section of the interior of the dome taken on the line :0 m, of Fig. 1, and in the lower left hand corner all parts of the dome broken away down to the plane of the line y-y, of Fig. 2. Fig. 4 is an inverted plan of the dome.

The furnace ,inclosure consists of the front end plate 1 which carries the door frames and flue-stop frames and the rear plate 2, which plates are provided with marginal flanges which support the outer jacket 5, and the inner lining 6 between which is a narrow air space 7 Fig. 2. The upper part of the lining 6, is perforated as at 8, 8, for the free passage of the heated air from the interior of the case to the pipes 32. An ash-pit 9 is fitted with the door 10 and damper 26 for the usual purposes of regulating draft and the removal of ashes and cinders, above which are the two sections 10 and 11 which form the fire-box proper, which is fitted with ordinary grates, 22, 22. N ear the bottom of the furnace is a flue-casting 13, 27, 28, which is of U shape, having one leg on each side of the fire box and a rear exit flue 16 to connect with the smoke pipe in the rear of the furnace. A diving flue 12 is located at the front end of each side flue 27 which supports and connects with the front end 0f the dome 15. This dome is a solid or integral structure having an opening through its floor or bottom wall which fits over the upper edge of the fire box. Its roof is arched and a web of connected flues 20, 20, extends on each side of the fire box from the floor of the dome chamber to its roof opening out through the floor and roof into the free air space between the incasement of the heater and its fire box. The flues 20 are inclined from their lower ends inwardly over the fire pot as much as possible and permit their upper openings to direct the air current passing through them immediately toward and into the pipes for distribution. This construction exposes their under surfaces directly to the radiation from the hottest part of the fire. This web of fines 20, 20, extends rearwardly only to the rear end of the fire-box leaving a space 15 between the roof or side wall of the dome and the backside of the flues 20, which space is utilized as a side flue to carry the products of combustion from the rear of the dome forwardly to the diving flues 12, 12, which connect with the bottom side flues 27 27 The feed door 36 of the furnace has a damper 37 and closes the front end of the dome, and just behind the back end of the fire box is a pipe 17 which passes through the dome vertically as seen in Fig. 2, and is removable so that as one burns out it may be taken out and replaced by a new one by simply removing bolts 18, 18, 18, when it will drop down into the bottom of the furnace. This pipe is termed a fender flue and it serves to deflect the current of heat from the fire boX laterally around the back end of the flues 20 to the side flues 45 as indicated by the arrows in Figs. 1 and 3. It also serves to act as a shield to protect the back end of the dome from the intense heat of the fire at all times but especially when the rear damper 23 is open.

A pipe 33 leads from the apron back of the feed door down between the front of the furnace and the end of the fire boX and opens into the ash pit. This serves as a dust flue, such as is found in heaters of this class.

From the rear of the dome 15 a smoke flue 16 extends back through the walls of the furnace, and from the rear of the fines 27 a similar short this 28 also projects out beyond the walls of the furnace. The exit pipe 29 is connected with these extensions by collars of the usual construction and in the upper one the flue damper 23 is located. This is fitted with a. cranked stem 24 to which the damper rod and handle 25 is attached so that it may be operated from the front of the heater in the usual manner.

The side fines 45 and 27 open out through the front of the heater as indicated at 39 and these openings are closed by the finestops 38, as more clearly illustrated in Fig. 1. These provisions facilitate cleaning the fines.

Mode of Operation of the invention-In starting a fire in the furnace the fine damper 23 is left open and the draft damper 26 may also be opened. This will permit direct circulation of draft from the fire box through fine 16 to the exit pipe 29 and thence to the chimney. When the flue damper is closed, the circulation, entering the inside of the chamber containing the furnace, either through the damper 26 or through passages which open into that chamber from the outside, passes through the fire box and thence upwardly and rearwardly, impinging in its course against the overhanging flue structure 20, 20, and thereby rapidly and intensely heating the same, while at the same time the most distant flames rise against. the pipefiue 17 and by it are deflected sidewise around the back edge of the casting forming the fines 20, 20, and returning in the side fines 45, thereby heating the sides of the fines 2O opposite the sides exposed directly to the fire, the current enters the diving fines 12, 12, and passing through them enters the lower return side fines 27. 27, and through them passes to the rear of the furnace and out through the exit pipe 28 to the chimney or to a pipe leading thereto. The roof and exterior walls of the dome are heated by the passage of the current from the fire box through the fines 45, and the direct exposure of the middle of the roof to the fire below. Thus, the air within the furnace between the jacket and the fire box becomes generally heated by direct radiation from the walls of the dome and the fire box as in other furnaces of this type, but its circulation in this furnace is greatly modified by the presence and location of the fines 20, 20, as will appear by reference to Fig. 1. Here it will be seen that the outlet openings 82 for connecting the distributing pipes with the furnace are placed in direct opposition to and over the discharge openings of the fines 20, 20. The result of this arrangement is that the temperature of the air within these fines is raised to a degree so much higher than that of any other part of the furnace that it ascends with great force and enters the open mouths of the distributing pipes above them. In its rapid passage it sets up an induced circulation and much of the heated air which otherwise would rise from at or near the bottom of the chamber directly upward along the outer incasement of the furnace to the exits above, is diverted in its course to the fines 20, 20, and in passing through them becomes more highly heated than it possibly could be without them, as in making its exit from their upper openings it shoots directly into the distributing pipes without coming in contact with any part of the furnace of a cooler temperature than the fines 20 from which it emerged. The fender pipe 17 operates as a heating fine in precisely the same way.

From. the foregoing it will appear that the amount of prime radiating surface within the furnace inclosure with which the air within the furnace comes in immediate contact in its passage from the lower part of the heater to the distributing pipes is materially increased by the introduction of the vertical fiues 17 and 20, 20. Also that the ascensive force of the hot air currents so initiated in the fines 20, 20 is so much intensified by the direct exposure of all Sides of mmh, fine to the hottest flames of combustion that the cir culation of the hot air through the distributing pipes throughout their entire extent is greatly improved.

1 therefore claim as my invention and desire to secure by Letters Patent the following:

1. In a furnace, the combination with the fire box, of a low down dome of integral construction resting upon the fire box, and comprising a top wall and oppositely disposed side walls, said side walls being curved inwardly so as to overlie the fire box and said side walls comprising a series of vertically extending continuously curved open ended hot air fines and an inclosing chamber the fines being in closed contact with one another so as to form substantially solid walls which terminate short of the rear wall of the dome to afiord communication with said inclosing chamber, vertically arranged diving fines communicating with said inclosing chamber, said diving fines projecting downwardly to a point adjacent the lower end of the fire box, a smoke outlet pipe having a fine connection with said inclosing chamber, a substantially U-shaped fine afiording communication between the diving fines and the smoke outlet pipe, and a deflector tube in said inclosing chamber of the dome at a point to the rear of said vertically extending fines, said deflector tube being removable.

2. In a furnace, an outer casing, a smoke pipe outside of the casing, a central casing forming an ash pit and fire box, a horizontally disposed substantially U-shaped fine surrounding the central casing, the opposite arms of which connect with the front wall of the outer casing and are normally closed, vertically extending relatively flat diving flues, one supported on each arm of the U- shaped flue and communicating therewith, a dome of integral construction supported on the wall of the central casing and having oppositely disposed sides curving upwardly and inwardly so as to overlie the fire box, said sides having a central partition extending from top to bottom, the space at the inside of the partition being divided into a plurality of vertically extending curved flues open at top and bottom, and the space at the outside of the partition being continuous and closed at its top and connecting at the bottom with the flat vertically extending flues, a horizontally extending pipe projecting from the dome to the outside and communicating with the smoke flue, a Vertically extending removable fender in the form of a tube in the dome in the outside space and in front of said horizontally extending flue, and the outer casing having air flue openings in the path of the upper end of the open ended flues of the dome.

3. In a furnace, the combination of a horizontally disposed outer casing having a dome shaped top, an inner casing having an ash pit and fire box, and an interposed grate between the ash pit and fire box, a relatively low down arched dome positioned on the wall of the fire box, said dome comprising two opposed series of abutting and connected vertically extended hot air flues open at the upper and lower ends outside of the fire box, the two series of flues being curved inwardly and connected to one another at the top so as to overlie the fire box and form a closed dome therefor, said dome having an inclosed space surrounding said vertically extending flues, which space communicates with the fire chamber at the rear of the furnace and at a point at the rear of said vertically arranged flues, a substantially U- shaped flue within the outer casing, at a point below said grate, the arms of the flue connecting with the front of the casing, and projecting around the sides of the ash pit section, and the loop of the flue connecting with a flue extension projecting through the rear wall of the casing, and vertically extending diving flues connecting the U- shaped flue with the inclosed space of the dome surrounding the vertically extending flues of the dome.

In testimony whereof I have hereunto subscribed my name in the presence of two witnesses.

THEODORE R. BRIEN. Witnesses:

EMILY Sco'r'r, JENNIE S. WALLWORTH.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

